Steam generating furnace



Aug. 18, 1936.

G. A. REHM 2,051,459

5 TEAM GENERATING FURNACE 2 Sheets-Sheet 1 Filed Nov. 9, 1934 y 62/8224 V A. EEHM Aug. 18, 1936. I RE M 2,051,459

STEAM GENERATING FURNACE Filed No v. 9, 19:54 2 Sheets-Sheet 2 35 3 vw OHM GUSTAV A. FEEHM Patented Aug. 18, 1 936 STEAM GENERATING FURNACE Gustav A. Rehm, Worcester, Mass., assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Application November 9, 1934, Serial No. 752,320

6 Claims.

This invention relates to steam generating furnaces, and more particularly to furnaces of the type having water tubes associated with the furnace walls to absorb radiant heat from the combustion flame and additional water tubes located in the path of the gases after they leave the combustion chamber.

One form of boiler in common use today i known in the art as a cross-drum boiler, and comprises a bank of inclined water tubes connected to headers at each end, the headers being connected by circulating tubes to a transverse horizontal steam-and-water drum. In boilers of this type the circulation is seriously restricted by lack of suitable provision for the release of the steam from the tubes, and this condition is aggravated if water wall tubes are arranged to deliver additional steam into the boiler headers. It is accordingly one object of the invention to provide a steam generating furnace having a steam boil-er and water walls so constructedand arranged that the steam from the water walls will be effectively released without disturbing the boiler circulation. 7

It is a further object of the invention to provide a steam generating furnace having a steam boiler of the cross-drum type; together with water walls so constructed and arranged as to deliver steam directly to the boiler drum without disturbing the boiler circulation.

It is a further object of the invention to provide a steam generating furnace having a steam boiler of the cross-drum type, together with water walls and slag screen tubes below the boiler tubes, the parts being so constructed and arranged as to avoid any disturbance to the boiler circulation as a result of steam released from the water wallsand slag screen .tubes.

-With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

, Fig. 1 is a longitudinal section through a steam generating furnace, the section being taken on the line l-I of Fig. 2; and

Fig. 2 is a section on the line 2-2 of Fig. 1.

In the drawings I have shown a steam boiler comprising a lower rear group of upright headers l0 and an upper front group of upright headers l I the headers of the two groups being connected by a bank of upwardly and forwardly inclined water tubes l2. A transverse horizontal steamand-water drum I4 is mounted above the rear headers I0 and is connected to these headers by vertical down-comer tubes [5. The drum is connected to the upper portions of the front headers H by means of horizontal tubes l6. Walls l8 form a furnace chamber beneath the boiler, and baffles l9 direct the hot gases as they flow from the furnace chamber across the tube bank l2 and thence to a gas outlet 20 adjacent to the drum I 4. The boiler as so far described is of well-known construction, and many are in use throughout the country.

In order to protect the furnace walls and at the same time obtain increased steam generation 15 through the absorption of radiant heat, it is desirable to provide water tubes at the boundaries of the combustion chamber. It is also desirable, when burning certain slag forming fuels, to provide a row of comparatively widely spaced water tubes below the boiler tubes to chill '7 the slag particles carried in suspension in the hot gases and prevent them from adhering to the boiler tubes. The upward flow of steam from the boiler tubes is seriously restricted by reason of the small flow area afforded by the front boiler headers l I and it is therefore important to avoid the release of additional steam to these headers.

In the preferred construction illustrated I have provided a row of upright water wall tubes 22 at the rear of the furnace, the lower ends of the tubes being connected to a transverse header 23, and their upper ends being connected to a transverse header 24 located near thelower ends of the rear boiler headers Ill. The lower header 23 is supplied with water from the boiler, preferably by means of a row of down-comer tubes 25 leading from the lower ends of the rearboiler headers. A row of slag screen water tubes 21 extends forwardly and upwardly from the upper header 24,

the front ends of these tubes being connected to a transverse header 28 located adjacent to the lower ends of the front boiler headers II. The slag screen tubes are comparatively widely spaced, both from each other and from the boiler tubes. A pipe or conduit 29 extends upwardly and rearwardly from each end of the header 28, and these pipes connect with the ends of a transverse header 3| located adjacent to the lower front surface of the boiler drum M. This header 3| is connected to the boiler drum by means of a row of tubes 32.

At each side of the combustion chamber I have shown a row of upright water tubes 34 with their lower ends connected to headers 35 and their upper ends connected to headers 36. The lower rear water wall header 23'by means of tubes 38.

The upper headers 36 are connected to the pipes 29 by means of rows of tubes 39.

At the front of the combustion chamber I have shown a row of upright water tubes 4| with their lower ends connected to a transverse header 42 and their upper ends connected to the header 28. The ends of the header 42 are connected to the lower rear water wall header 23" by means of pipes 43.

The operation of the invention will be apparent from the above disclosure. A suitable fuel, such as pulverized coal, is burned in the combustion chamber, and the hot gases fiow incontact with the boiler tubes I2 and escape through the outlet 20. Water circulates downwardly from the drum I l through the tubes I5 to ,the,. headersl I0; for:

wardlythrough the tubes I 2 to the headers I I, and.

thence rearwardly through the tubes IE to the drum, where the steam is liberatedrand with: drawn to a place of use. Water also flowsfrom the headers llldownwardly through the tubes 25 to the header 23, and upwardlythrough the; tubes 22, header 24, tubes 21, header 28,,pipes, 29, header 3| and tubes 32 to the drum. The lower-side water wall headers 35 receive water from the header 23. through the tubes 38 and this, water flowsiup wardly through the tubes; 34,, headersv 36 and tubes-39 to the pipes' 29, The lower front water wall header i2 receives water from the header 23 through the pipes 43, and, this water; flows up-.

wardly through the tubes ,4] to the reader 28,.-

The water wall tubes 22, 34, and 4 I not only priotect-the furnace walls, but they also. absorb radiant heat at ahigh rate and thus generate large quantities of steam. 'The, slagscreen tubes2-l cool the upwardly, flowingv gases. sufiiciently. to prevent slag carriedv insuspensionin the gases from adhering to the boiler tubes. The construction is comparatively simple and inexpensive, and thereis ample flow area forrthe release of steam generated in the water wallsand slag screentubes without interfering with the boilercirculation. 7 Havingthus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A steam generating furnace comprising a lowerrear group .of upright'headers, an upper front group of upright headers, a bankof upwardly and forwardly inclined water tubes connecting the groups of headers, a transverse steam and-water drum arranged to supply water to the lower headers and to receive steam from the upper headers, a transverse header located adjacent to the lower ends of the upper headers, a row of steam generating tubes-arranged to deliver steam- 7 tubes connecting each longitudinal headerwith' the upwardly and rearwardly inclined pipe thereabove." a

2. 'A steam generating furnace comprising a lower rear group of upright headers, an upper front group of upright headers, a bank of upwardly and forwardly inclined water tubes connect-ing the groups of headers, a transverse steamand-water drum arranged to supply'water to the lower headers and to. receive steam from" the up- Perheader ransverse header located adjacent to the lower ends of the upper headers, a row of transverse header, means including water wall tubes at each side of the furnace arranged to deliver steam to said pipes, a second transverse header connecting the rear ends of the pipes, and

tubes connecting the second transverse header with the drum.

3. A steam generating furnace comprising a.

"lower rear group of upright headers, an upper front group of upright headers, a bank of upwardly andforwardly inclined water tubes connecting the groups of headers, a transverse steamand-water drum arranged to supply water to the lower headers and to receive steam from the V upperfiheaders,atransverse header located adjacent to the lower ends of the upper headers, a row ofupwardly and forwardly inclined slag creen tube n c ed] at heir. upper ends;v 0 the transverse header, means including pipeseictendingupwardly andrearwardly from theends ofthe transverse header to deliver, steam there: from to the drum, and means includin water wall tubes at each side'of the furnace arranged to deliver steam to said pipes. .7 I .7

4, A steam generating, furnace comprising a bank of inclined water tubes connected at each; end to upright headers, aitransverse steam-,anda water drum arranged to supply water to. thelowet headers and to receive steam from the-upper headers, a transverse header located adjacent'to the lower ends of the upper headers, a second transverse header located adjacent, to the .lo wer ends of the lower headers, inclined slag screen tubes connecting the two transverseheadersupe ri ht water wall tubes connectedat their upper.

ends to the second transverse header, a. third transverse header adjacent to the drum and con-j nectedthereto by a row of tubes, pipes connect: ing the respective ends of the first and third trans: verse headers, a longitudinal header beneath each pipe, upright water wall tubes connected at their upper ends to the longitudinal headers, and tubes connecting the longitudinal headers with the pipes thereabove. 7 f

5. A steam generating furnace comprising a bank of inclined water. tubes connected at each end to upright headers, a transverse steam-andwater drum arranged to .supply water to the lower headers and to receive steam from the upper headers, a transverse headercloca'ted adja cent to the lower ends of the upper headers a' second transverse header located. adjacent to the lower ends of the lower headers, inclined slag screen tubes connecting the two transverse head ers, upright water wall tubes connected at their upper, ends to the second transverse header, a third transverse headeri adjacent to the drum and connected'thereto by a row of tubes, pipes connecting the respective ends .of the first and" thirdtransverse headersa longitudinal headerbeneath each pipe, upright water walltubes-con nected attheir upper ends .to the longitudinal headers, tubes connecting the longitudinal headerswith the pipes thereabove, headers connected to the lower ends of all the water wall tubes; and water supply connections to the last mentioned headers. 6. Asteam generating furnace comprisinga bank of inclined water-tubes connected at each end to upright headers, a transverse steam and-f water drum arranged to supply water m the lower-headers and to receive steam from the up per headers, a tranverse header located adjacent to the lower ends of the upper headers, heat exposed tubes arranged to deliver steam to the transverse header, a second transverse header adjacent to the drum, a row of tubes connecting the second transverse header to the drum, pipes connecting the respective ends of the two transverse headers, a longitudinal header beneath each pipe, upright water wall tubes connected at their upper ends to the longitudinal headers, and tubes connecting the longitudinal headers with the pipes thereabove.

GUSTAV A. REHM. 

